Fix scrollbars not updated when zoomed inout

[Steve-Mcl]

fixes #30

Description

• Apply the scroll bar sizes to the correct part of the SVG
• build minified version
• bumps v to 0.3.1 in readiness for immediate publishing

Related Issue(s)

30

Checklist

• [x] I have read the contribution guidelines
• [ ] Suitable unit/system level tests have been added and they pass
• [ ] Documentation has been updated
  • [ ] Upgrade instructions
  • [ ] Configuration details
  • [ ] Concepts
• [ ] Changes flowforge.yml?
  • [ ] Issue/PR raised on FlowFuse/helm to update ConfigMap Template
  • [ ] Issue/PR raised on FlowFuse/CloudProject to update values for Staging/Production

Labels

• [ ] Includes a DB migration? -> add the area:migration label